/**
 * @file 07.c
 * @author your name (you@domain.com)
 * @brief 检查质数
 * @version 0.1
 * @date 2022-04-13
 * 
 * @copyright Copyright (c) 2022
 * 
 */
#include <stdio.h>

int main()
{
    int n, i, flag = 0;
    printf("Enter a positive integer:");
    scanf("%d", &n);
    for (i = 2; i <= n / 2; ++i)
    {
        // condition for nonprime number
        if (n % i == 0)
        {
            flag = 1;
            break;
        }
    }
    if (flag == 0)
    {
        printf("%d is a prime number.\n", n);
    }
    else
    {
        printf("%d is not a prime number.\n", n);
    }
    return 0;
}